davidson



J. DAVIDSON.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY 7, I919.

PatentedSept. 30, 1919.

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J. DAVIDSON.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY 1.1919.

lfiw we Patented em 30,1919.

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J OHN DAVIDSON, OF MANCHESTER, ENGLAND.

INTERNAL-COMBUSTION ENGINE;

arissa Specification of Letters Patent.

Patented septa 3(1), 1919,,

Application filed July 7, 1919. Serial No. 309,145.

To all whom it may concern:

Be it known that l, JOHN DAvmsoN, a subject .of the King of Great Britain, residing at Manchester, in the county of Lancaster, England, have invented certain useful Improvements in and Connected with Internal-Combustion Engines, of which the following is a specification.

This invention relates to improvements 1n and connected with the two cycle type of internal combustion engines, such as described in my British application for Letters Patent No. 119,401, dated March 19th 1918, in which the charging piston works in tandem fashion with and forms a tubular extension of the working piston and passage between the charging cylinder and the work ing cylinder and having ports serving also as a valve controlling the distribution or the mixture to the charging and working c'yhnders.

The object of this invention is the provision of means whereby the said type of engine is rendered applicable for large power and simplicity and compactness of construction and efiiciency in action are combined,

1 attain these objects by the means illustrated in the accompanying drawings which illustrate a single acting integral combustion engine constructed in accordance with this invention,

Figure 1 being a longitudinal vertical section and Fig. 2 an end view thereof. 7

Referring to the drawings, which illustrate a single acting engine constructed in accordance with this invention, a and h are respectively the working cylinders and pistons, and and d, the charging or pump cylinders and pistons arranged tandem, c are the tubular extensions of the working pistons 25 at the top provided with the charging or pump piston 65. a are the exhaust ports in the end of the working cylinders.

In connection with each of the said charging or pump cylinders 0, a piston valve f is employed actuated from the crank shaft 9 of the engine by an eccentric. h and adapted to wntrol the inlet to and delivery of aird' and] from the top side of chargin piston to control the inlet to and elivery of gas or mixturerfrom the bottom side of the chargin or pump piston cl.

To 0 tain a definite pure air scavenge, the pure air and mixture are supplied by separate main pipes 2, k, the pure air pipe i being connected with the top ends and pipe is with the bottom ends of the piston valves f, the pure air being admitted to the topof said valves.

The charging or pumppistons al simply act as compressors, the air being compressed on the top side and delivered into the main pure air pipe 2' and the mixture being compressed on the underside and delivered into the mixture main is.

The tubular extension 6, moves in barrels m arranged concentrically between the working and charging or pump cylinders a, and 0 respectively and having ports as connected with said main mixture supply pipe is, through which the mixture is admitted, each time the ports 0 in the tubularextensions 6 meet the ports n.

The top of each charging or pump cylinder 0 has a centrally extending casing 32 in which moves the open upper end of a tube 9 the lower end of which is secured into the tubular extension e and has radial ports 1- adapted to register with inlet ports 8 in the end of the working cylinder 0;,

The said casings p by means of elbow pipes t, are connected with the main pure air supply pipe 71 to permit of pure air passing down the tubes 9 and through the ports 7* and 8, enter the working cylinder 0 and thus throughly scavenge the same immediately the exhaust ports a of the engines have been opened.

The engine described operates as folii? a v s a rea .y explained the char in um c, d has a dual function. T he t op sihle 0% piston d is used to compress air to a few pounds per square inch which is delivered into main 5 and the bottom side oi the piston d is used to compress the'mixture which is delivered into main kn It will thus be seen that pipe 2' is always charged with air at a small pressure and pipe with mixture at a small pressure.

As the working piston 6 moves downward, it first uncovers the exhaust ports a and allows the burnt gases to escape, as the piston moves farther down the small ports 0" overrun ports 8 and allow pure air to enter the working cylinder to scavenge out the burnt gases, and immediately this has taken place the mixture flows in and charges the working cylinder. On the return stroke, the air mixture, and exhaust ports are cut ed and the mixture compressed and when the piston is nearing the top of its stroke, the mixture is fired in the usual manner.

I claim 1., In an internal combustion engine of the two cycle type, in combination, a working and a charging cylinder, a barrel between same, a piston in said working cylinder having a tubular extension adapted to reciprocate in said barrel, a piston on the free end of said extension adapted to reciprocate in said charging cylinder, a fresh air inlet tube concentrically secured into said extension, a charging cylinder cover having externally a casing lnto which the free end of said tube projects and ports in the secured end of said tube adapted to register with ports in the respective end of said barrel.

2., In an. internal combustion engine of the two cycle type, in combination a working and a charging cylinder, a barrel between same, a iston in said working cylinder having a tu ular extension adapted to reciprocate in said barrel, a piston on the free end of said extension adapted to reciprocate in said charging cylinder, mixture inlet ports in arness each end of said barrel and two sets of mixture inlet ports in said extension adapted to register with the said barrel ports and convey mixture through said extension from the harging cylinder into the working cylinder, for the purpose specified.

' 3. In an internal combustion engine of the two cycle type, in combination, a Working and a charging cylinder, a barrel between same, a piston 1n said working cylinder having a tubular extension adapted to reciprocate in said barrel, a piston on the free end of said extension adapted to reciprocate in said chargin cylinder, a main .pure air supply pipe an a main gas supply pipe, a piston valve located between said two main supply pipes and each of said charging cylinders for conveying pure air and mixture from the respective ends of said charging cylinders to said main pipe, for the purpose specified,

Signed at Manchester, in the county of Lancaster, this 25th day of June, 1919.

JOHN DAVIDSON. Witnesses:

ALFRED BOSSHARDT, MARY T. Bossnxno'r. 

